The work is devoted to the issue of assigning the size of a security area during the TTS LNG bunkering using the tanker-ship method. The initial data for the calculation scenario (leak location, equipment susceptible to damage, pressure and parameters of LNG inside the bunkering hose for liquid phase of LNG, dimensions of the hose for transferring bunker LNG) obtained during the risk assessment of this operation were proposed. When solving this problem, the LNG expiration rate was determined in two ways — according to the original methodology of Prof. V.A. Pavlovsky and the approximation from the IEC 60079-10-1:2021, which showed the same results. The results of the study can be used to determine the size of the security area when planning LNG bunkering using the tanker-ship method. The research materials of domestic and foreign scientists, as well as relevant guidance documents, are summarized and analyzed.

   The paper examines the regulatory framework for climate projects in water transport.

   The purpose of the study is to obtain a logical sequence of actions to assess the applicability of a particular type of climate project in water transport.

   The purpose of the study is to demonstrate the implementation of the expert assessment method to determine the reasonability of creating a climate project in accordance with the proposed criteria, as well as to compare climate projects with common goals and differing in execution.

   The research materials of domestic and foreign scientists, as well as relevant guidance documents, are summarized and analyzed. The study demonstrates the regulatory framework for the application of climate projects, as well as outlines the main ways to assess the applicability of climate projects in water transport. Further actions of the authors will be to assess the attractiveness of the participation of stakeholders in climate projects related to making changes to the design or device of the vessel in order to meet the formal characteristics of the climate project.

   The purpose of this article is to assess the impact on the marine industry and determine the consequences of the entry into force of new Russian regulations governing greenhouse gas emissions.

   The article compares the requirements of the regulatory documents of the strategic planning of the Russian Federation on emission control and IMO documents. There are certain discrepancies in the methods of calculating CO₂ emissions in accordance with IMO and related Russian documents. The differences in the conversion rate of one ton of fuel to CO₂ indicated in these regulatory documents have been identified. It is concluded that the requirements of Annex VI to MARPOL and 296-FZ are duplicated for ships with a gross tonnage of more than 5,000 tons, which may lead to double reporting and duplication of greenhouse gas reduction measures in future. The impact of RFGD No. 355 on the industry was assessed by comparing the scope of its application with data on CO₂ emissions from Russian-flagged ships.

   The main provisions of the concept of full autonomy of maritime autonomous and remotely controlled surface ships (MASS) are given. The study of this issue allows to develop the structure of the automatic control system of a MASS ship. The goal is to help the designer develop the concept of ACS MASS. The stages of solving the problem of developing the structure of the MASS control system are in accordance with the requirements of the Regulations on the Classification of Marine Autonomous and Remotely Controlled Surface Ships of the Russian Maritime Register of Shipping. The list of information sources forming situational awareness of the management system is formulated. The minimum necessary evidence has been determined that the concept presented by the designer ensures a safety level of the MASS equivalent to or better than that of a conventional ship.

   The relevance of the chosen research topic is explained by the active development of autonomous navigation and the need to solve problems arising during the operation of marine autonomous surface ships.

   This paper provides an overview of some models for predicting motions of a ship in irregular waves, built on the basis of artificial neural networks. The practical advantage of the considered approaches lies in the possibility of their application as part of relatively low-performance onboard computing systems of autonomous ships, where it is economically impractical or technically impossible to place high-performance computing clusters, and the calculation results should be obtained in real time. It is concluded that the calculation results obtained using the considered models have a significant error in predicting the ship's motions parameters near the extremes of the curve of the angles of rolling and pitching, which calls into question the safety of their application.

   The object of the study presented in the paper are the structures of ship hull subjected to the long-term influence of low ambient air temperature.

   The subject of the study are the methods aimed to define the value of design air temperature required to select the steel grade for hull structures.

   The methods addressed in the paper are based on the industry regulatory framework. The following requirements have been reviewed: rules of Russian Maritime Register of Shipping, International Association of Classification Societies, International Maritime Organization, Finnish-Swedish Maritime Administration, and US Coast Guard rules. The calculations of design temperature have been performed, which are based on the available Russian climate database for several observation points. The calculations cover the period of 2013—2024 for winter season in the eastern part of Baltic Sea (Gulf of Finland) and Northern Sea Route area. The comparison is made between different probability theory methods and statistics applied to define the value of design air temperature. Normal law parameters have been calculated for all the selected observation points. Eventually, the design temperatures have been calculated which are based on probability theory methods.

   An important aspect of Russian national interest protection in Arctic is the application of shipbuilding steels ensuring no cases of brittle fracture at low service temperatures. Cold resistance of steels is verified by special mechanical tests, their required results should have a calculated substantiation. This paper considers finite element method (FEM) simulation of structural members made of steel plate and specimens and gives a description of suggested conditions of concurring brittle and ductile fracture. Local fracture conditions connect a brittle fracture event with an attainment of a critical first principal stress to stress intensity ratio while a ductile one with an accumulated plastic tear and shear strain. Their simultaneous application allows the simulation of fracture appearance and quantitatively assessment of the interrelation of different parameters, e. g. in case of drop weight tear test, the shear portion and impact energy, as well as the fracture toughness needed to arrest a crack in a typical structural element. The above technique gives an opportunity of the required ductile-to-brittle transition temperatures substantiation.

   A methodology and algorithm for constructing dependencies for determining the parameters of calculated ice loads on the on-board structures of ice navigation vessels based on a new model of dynamic ice destruction (MDRL) are described. The theoretical foundations of MDRL are considered. To construct the calculated dependencies, representative statistical information on the shape of the hull of ice navigation vessels was collected and analyzed in a wide range of displacement and for various ice classes. Based on the systematization of this information, it is proposed to divide ships into several groups, differing in the values of hull shape parameters at the level of the calculated waterline. The initial data for performing calculations of ice loads according to the new model are substantiated. The structure of the initial data is determined by the experiment design matrix — a numerical experiment using specialized software. The calculated dependencies are presented in the form of quadratic regression dependencies. The adjustment of the calculated dependencies for determining the parameters of ice loads is based on calculations of ice loads for real ships. The results of practical testing of the calculated dependencies are presented. The results obtained can be used to improve the requirements of the Rules of the Russian Maritime Register of Shipping.

   Ships with wide deck openings play a crucial role in modern maritime logistics and cargo transportation. However, the design and operation of such vessels are associated with several technical challenges, including issues related to the strength and rigidity of their hulls. Traditional deck framing systems form a structure consisting of beams intersecting at right or nearly right angles, creating a system of rectangular frames. These frames exhibit relatively low stiffness under shear deformations that occur during hull torsion.

   In this context, the relevance of the work is determined by the proposal to increase the shear stiffness of the hull plating by introducing diagonal elements into the framing system.

   Such a framing system can be referred to as diagonal. It transforms rectangular frames into triangular ones, significantly enhancing their resistance to shear. The work is aimed at developing a diagonal framing system for the side plating on ships with wide deck openings, ensuring stiffness and strength in accordance with the requirements of the Russian Maritime Register of Shipping.

   The article is devoted to the optimization of a two-stage bevel spur gearbox to minimizing the mass of gears. The minimum weight and overall characteristics of the gearbox are its important competitive advantage. In designing multi-stage gearboxes, gear ratios should be selected in stages that ensure the mechanism has a minimum dimension. The optimal choice of gear ratios of the stages effect on the volume and the weight of the gears in each stage. A review of the available publications on this topic indicates a different intensity of analysis of the interrelationships of the operational and design parameters of the mechanism. The theoretical studies conducted by the authors showed that the results of dividing the gear ratio of the gearbox into stages are influenced primarily by the amounts of torque on the output shaft and of overall gear ratio, the type of heat treatment of the gears and a number of structural limitations. Objective function has been created taking into account the listed factors and represents minimized volume of gears. The search for the minimum objective function was carried out within the specified ranges of geometric and strength parameters of the parts and units of the gearbox, as well as its performance. The minimization results are presented as a function of the gear ratio of the spur stage and the overall gear ratio, the heat treatment of the gears and the torque on the output shaft. The results of calculation of the minimum allowable gear ratio of the spur stage depending on the gear ratio of the two-stage bevel spur gearbox are also given, in which there is no, in particular, cutting of the low-speed shaft and introduction of the milling cutter into the support neck of the bevel shaft; shows comparison with existing guidelines.

   The article analyzes the current state of the low-speed marine engines (LSME) market. The main requirements for marine engines put forward by the International Maritime Organization (IMO) in terms of energy efficiency and emissions of harmful substances are given. Further ways of improving LSMEs in terms of reducing CO₂ emissions by switching to carbon-free marine fuel — ammonia — are briefly considered. It is shown that in the absence of the possibility of acquiring a license for the production of such engines, the organization of our own LSME production in Russia within a reasonable time frame is unlikely. A brief overview of the design and history of development of free-piston engines and their use on ships as LSMEs is given. The possibility of replacing LSMEs of a classical design with free-piston engines is shown, taking into account modern requirements for environmental friendliness and efficiency of marine engines. Information is given on the progress of work on a project demonstrating the capabilities of free-piston engines as LSMEs.

   The author's task is to draw attention to a way of developing domestic marine engine-building based on free-piston technology as an alternative to traditional LSME.

   The article discusses the issues of computational support for the design of shipboard ballast heating systems. The ballast tanks of the vessel, which receive seawater, must be equipped with a heating system to prevent freezing of the water. Heating is carried out by heat carriers circulating through coils installed in tanks. Determining the lengths of coils and the flow rates of heat carriers is an urgent task, given the lack of information on this issue contained in the industry regulatory and technical documentation. Currently, there is no appropriate software available to solve this computational problem, which leads to the need for analytical calculations. The paper provides general information about the design and principle of operation of ship's ballast heating systems and a recommended standard calculation algorithm. The article also contains an example of calculation for a conventional tank of known dimensions.

   For such vessels as ferries, tugs, minesweepers, special vessels designed to perform work on the sea shelf, high maneuverability is an important indicator. A unique opportunity to achieve high maneuverability of the vessel is provided by the use of a winged propeller. It essentially performs the functions of a rudder propeller complex, since it combines the advantages of a variable pitch propeller and an active rudder. A vessel equipped with winged propellers can smoothly change speed and direction of movement, turn on the spot, move sideways (i.e. with its side ahead). However, the widespread use of this type of propeller is constrained by the complexity and high cost of both the propeller itself and the hydraulic system used for remote control. The article discusses a method for simplifying the design and manufacture of a winged propeller control system through the use and adaptation of design modules included in the remote control system of the main marine diesel engine.

   The purpose of the article is to consider the problems of dual-circuit and single-circuit cooling systems to improve reliability.

   The article discusses the causes of accidents on ships related to flooding of engine rooms due to corrosion damage to pipes and elements in two-circuit cooling systems. It is pointed out that, despite the regulatory requirements of the Register aimed at improving the reliability of such systems, the problems of corrosion wear of pipelines remain relevant and affect the operation of ships. To completely eliminate the dangers of flooding, it is proposed to use single-circuit systems with outboard coolers more widely. The main limitation for the wider use of outboard heat exchangers is noted: a low heat transfer coefficient due to the natural circulation of outboard water in a warm box and restrictions in the Register Rules for the use of keel coolers for ice-class vessels. To expand the use of outboard coolers on ships, it is proposed to introduce a new type of cooler in the Register Rules, the definition of which is proposed to be added to the Register Rules. This will make it possible to apply less stringent requirements to such coolers compared to keel coolers, which will expand their use on ice navigation vessels. To intensify heat exchange in outboard coolers, measures are proposed to optimize the design of thermal and kingston boxes by organizing natural circulation in them or creating forced circulation of outboard water through the cooler using a water jet ejector using a fire protection system.